That is not true. We can detect the presence of a thing by the observation of something it causes. That does not imply we have a good definition of the thing.
At that point, we can only define it as something that causes this observation. And that is not very useful.
We might both agree its a poor definition, but at least it's a poor definition that's observable and neutral. That's useful in regards to this conversation.
Where as the other answer is simply "I can't say, but it's not [this]" and that isn't useful at all. It's simply opinion, which is literally the worst definition around. Personally, I don't define intelligence as "whatever qsera acknowledges as intelligence with no qualifying context"...
I have a two year old that can't count. She can definitely walk around, talk, eat, and do all sorts of other things that I would argue indicate some form of intelligence.
Same for my dog.
Same for entire cultures, including adult humans (anumeric cultures).
Arguably, they're constantly doing calculus, because they can walk, throw, catch, etc - but none of them can count.
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That said, to the point of my original comment - forcing a definition was absolutely useful, because it allows a more detailed and interesting conversation than "qsera doesn't believe an LLM is intelligent".
I agree that one is a poor definition, though. I also don't really think it rules out LLMs.